Background: Jaundice is the most common clinical problem among the newborns. Prolonged jaundice in the neonate is defined as a jaundice that lasts longer than 14 days and has multiple possible causes. This study aimed to evaluate the causes of prolonged jaundice in newborns referred to Shahid-Beheshti hospital, Kashan, Iran.

Materials and Methods: This cross-sectional study was conducted on 237 neonates with prolonged jaundice referred to Shahid-Beheshti hospital in Kashan. Clinical prolonged jaundice was defined as the yellow discoloration of the skin and mucous membranes, and persisting beyond 14 days of age. Blood tests were performed to determine the causes of jaundice.

Results: None of the infants had a direct hyperbilirubinemia. Breast milk jaundice (59.1%) was the most common cause of newborn jaundice and other possible causes were urinary tract infection (12.2%), Glucose-6-phosphate dehydrogenase deficiency (9.7%) and hypothyroidism (6.3%). The exact etiology was unknown in 12.7% of the cases. Moreover, while there was a relation between the incidence of neonatal jaundice and sex, no relation was seen between the incidence and age, weight and the initial bilirubin level.

Conclusion: Although the most common cause of prolonged jaundice is breast milk jaundice with no serious complication, a detailed investigation is recommended to determine the other important causes of the disease.